Chicago Mayor Rahm Emanuel says tougher gun laws are key to the city's crime-fighting strategy and he plans to protect the legal integrity of a firearms ordinance. Part of the ordinance was overturned by U.S. District Judge Samuel Der-Yeghiayan (der-YAY'-gen), who took aim at the section used to deny a permit to a man because of a prior misdemeanor conviction. The judge called that section "unconstitutionally void for vagueness." Emanuel on Wednesday refused to say whether he would appeal the ruling or rewrite the overturned section. Chicago's gun law took effect in 2010. It was passed days after a U.S. Supreme Court ruling struck down a 28-year ban on handguns. The ordinance requires gun owners to obtain a gun permit and register their firearms with the police.